Spinal surgeons are required to implant a variety of rods, screws and plates into the bony skeletal structure of the spine to correct a variety of misalignments and repair damage that exist between the vertebral bodies. A particularly useful procedure involves the placement of rod receiving spinal implants with pedicle screws into the vertebrae. These rod receiving implants commonly have a slotted “U” shaped body with a pedicle screw extending from the base of the slotted body. When the surgeon implants these devices in the bones along the portion of the spine to be corrected, he must then connect two or more of these implants using fixation rods. The fixation rods are typically solid round cylindrical metal devices that can be straight or curved. The rods must be driven inwardly to be seated to fit between the “U” shaped slotted body. Once in a seated position, the rod can be fixed rigidly into the rod receiving implant by tightening a set screw into the threaded legs of the slotted body clamping the fixation rod securely to the slotted body.
One difficulty for the surgeon is aligning the fixation rods with the slotted rod receiving implants and moving the rod inwardly toward the slot. This is particularly difficult when the implants need to be positioned to correct a preexisting misalignment. This aspect of positioning the rod is called reduction or reducing and a variety of elongated tools have been developed to facilitate the proper placement of fixation rods.
The present invention, as described hereinafter, is an improved tool assembly that can easily be clipped onto a rod receiving spinal implant and reduce a fixation rod, and while clipped in place, deliver a set screw to fix the rod in a proper position to achieve the corrective spinal alignment and support for the particular surgery.
These and other objectives are achieved by the invention as described hereinafter.